TiO_2光催化降解直接耐酸大红的动力学研究

Kinetic Study on Photocatalytic Degradation of Direct-red 4BS by TiO_2

以TiO2为催化剂,直接耐酸大红4BS为模型污染物,对暗吸附实验和不同光强下的光催化反应进行了研究。实验结果表明,TiO2对4BS有很强的吸附作用,其原因主要与染料的结构特性和催化剂表面物种有关,由于高吸附作用导致光催化反应为零级动力学;反应速率r随起始浓度C0的增加变化不大,随着光强的增强,反应速率逐渐加快,但当光强大于1.48 mw/cm2,变化较小达到光饱和;通过分析推测光催化反应途径主要是羟基自由基.OH与吸附在催化剂表面有机物的反应。

In order to clarify the photocatalytic mechanism,photocatalytic degradation kinetic parameters were experimentally investigated under different light intensity with commercial TiO2 as the catalyst and direct-red 4BS as the model compound.To account for the results of dark adsorption,significant adsorption occurred on the surface of catalysts,the main reason was that 4BS possessed of-SO-3 groups and TiO2 surface existed TiOH+2,because of significant adsorption the photocatalytic degradation would observed ze...